The new Barneys Coop on Atlantic Avenue is the perfect place for well-to-do Brooklyn fashionistas — but you need more than money to shop there.

You need hips like Kate Moss.

Otherwise, you’re too fat for Barneys.

The store opened last Thursday, so I headed right over to browse for something suitably sleek. I quickly found a fantastic No. 6 cocktail dress in black with a watercolor print and ruching on the side. After my initial sticker shock — It’s $315? Well, it is pure silk — I couldn’t help but try it on, if only to dream.

Barneys only offers three sizes of the dress: one, two and three, which, I was told, correspond to small, medium and large. I grabbed dresses in size two and three and headed to the fitting room. I’m a small or medium everywhere I’ve shopped, but I took the large because the dress looked like it ran small.

The medium was too small, but I figured that the large would fit fine — but I couldn’t even get it over my hips! As much as I pulled and tugged, it wouldn’t budge.

And it happened with other garments, too.

Look, I know I’m no 1990s-waif-look cover girl, but I’ve never not fit into a large of anything — in fact, a large is usually too big.

Then it hit me: As fashionable as I consider myself, am I too fat for Barneys?